Dual Motor Bidirectional Drilling

ABSTRACT

The present invention discloses methods and apparatus for utilizing a downhole electric motor or motors for drilling in a well casing using a combination retrieval/electric conduit cable capable of reliability supplying sufficient electric power to drive the electric motor(s) and other components or a separate retrieval cable and electric conduit where the electrical conduit in attached to or disposed in the casing pipe wall. The electric motors may be combined with mud motors. The casing may be a combination drill pipe/casing in which the combination drill/casing pipes is rotated to rotate the drill bits, preferable in combination with downhole drive motors.

BACKGROUND Field of Invention

This invention is in the field of drilling wells and specifically in methods and apparatus for utilizing a downhole electric motor or motors for drilling in a casing with retrieval and electric cable(s) capable of reliability supplying sufficient electric power to drive the electric motor(s) and other bottom hole assembly components.

Background

Conventionally, in the drilling of wells, particularly oil and gas wells, a substantial pipe, commonly referred to as “drill pipe”, with heavy weight connecting devices is used. These pipes must withstand the required tensional, torsional and pressure forces along with the repeated coupling and uncoupling necessary to change, replace or modify the downhole drilling devices are used to rotate drilling devices and provide a conduit for the “drilling mud” that cools, lubricates and cleans them while carrying the resulting drilling debris back to the surface. The “drilling mud” is used to remove cuttings and debris from the drilling operation, clean and lubricate the down hole devices, control hydrostatic forces, temporarily line and protect the hole while being drilled, and “float” the casing installations as may be required. This heavy drill pipe then requires heavy weight, high strength surface equipment powered by high horsepower drives to achieve the required makeup and breakout torques required for fluid seal and tensional strength to manipulate this heavy weight of conventional drill pipe. Then after drilling the hole to a desired depth the drill pipe is removed and a lighter weight and larger diameter pipe, commonly referred to as “casing” is installed and cemented in place to line and protect the already drilled hole. Subsequently, a smaller diameter hole is drilled through the previously installed casing and continued below the casing to another desired depth. The drill pipe is removed again and another section of casing is installed and cemented in place to line and protect the smaller newly drilled hole. This process is repeated until the desired depth is reached and the final casing to line and protect that final section of drilled hole has been installed and cemented.

When the drilling bit or any other part of the bottom hole assembly or drilling device is required to be replaced or modified all the drill pipe must be uncoupled and withdrawn from the well and generally placed in a surface racking device as so provided. After the drilling device or any other part of the bottom hole assembly (BHA) has been repaired, replaced or modified, all the drill pipe must be removed from the racking device reconnected and re-inserted into the well bore that has already been drilled to resume and continue the process of actual drilling. This is a very labor intensive and time-consuming process creating substantial wear and tear on all the associated equipment during which time no progress in drilling the well is realized. It is common that a substantial percentage of the total operating time to drill a well is consumed by the unproductive drilling time that is necessary to withdraw and reinsert all the drill pipe to replace any part of the BHA depending on the depth of the well being drilled. During this operation, known as “tripping” the walls of the hole and the drill pipe are at risk of being damaged, the pipe becoming stuck or pressure control being lost due to the lack of circulation during this process.

The casing provides the interior operating space for the completion equipment used to produce from any formation that may have been encountered. Therefore, one type of heavy wall pipe is used for the drilling operations and another type of lighter wall casing pipe is subsequently used for protecting the resulting drilled hole. Conventionally the initial hole drilled must be of a sufficient size to allow for the installation of succeeding smaller casing sizes as the wells reach depths exceeding the design tensile and bursting strengths of the uppermost pipes and the collapse strengths of the lowermost pipes, and still allow for the final casing to be large enough to accommodate additional strings of production assemblies, which may include several tools known to those skilled in the art. The result must provide protection of the drilled hole, pressure control, clearance for cementing the annular space between the drilled hole and the casing, provide a protective string to the walls of the drilled hole to isolate and manage the various formations that were penetrated and clearance for subsequent internal operating and production equipment.

The necessity of using one type of pipe for the drilling and tripping operations and subsequently replace it with another type of pipe used to line and protect the resulting drilled hole is a significant problem in this conventional method of drilling. A further disadvantage is the unproductive time in spent in removal and reinsertion of all the drill pipe to renew the drilling device or modify the bottom hole assembly.

A more modern drilling system consists of a motor that supplies rotational force to the drilling device that is powered by circulating drilling mud pumped from the surface. Thus, it is not required that the drill pipe to be rotated to provide rotation to the drilling device. This allows some of the difficulties with the separate drill pipe/casing system to be partially overcome and eliminates the need for rotating drill pile. In general, the motors used in this service are “Mud” motors, that is, motors driven by the flow of “drilling mud”. In this operation, heavily built surface equipment is used to pick up pipe, circulate drilling fluid, and raise or lower the pipe, to pick up the next pipe, insert and rotate or lower it, depending on the type of bottom hole assembly being utilized. The circulated drilling fluid is also used to maintain pressure control during the process and protect the well bore.

This operation is efficient since drilling mud is usually flowing, but lacks flexibility and can be underpowered. Electric motors have been used and are generally preferred, but have the disadvantage that sufficient constant electric power is difficult to provide. What is needed is an efficient way to provide electric power to drive an electric drilling motor. Such a means can also be useful in providing needed communication wiring for accessing down-hole data. The present invention provides such means.

SUMMARY OF THE INVENTION

The present invention comprises methods and apparatus for utilizing a downhole electric motor or motors for drilling in a well casing using a combination retrieval/electric conduit cable capable of reliability supplying sufficient electric power to drive the electric motor(s) and other components or a separate retrieval cable and electric conduit where the electrical conduit in attached to or disposed in the casing pipe wall. The electric motors may be combined with mud motors. In some embodiments, the casing may be a combination drill pipe/casing in which the combination drill/casing pipes is rotated to rotate the drill bits, preferable in combination with downhole drive motors.

In some embodiments, composite polymer drilling/casing pipe is preferred for attaching electrical connections because the wiring can be incorporated in the wrapping during manufacture and electrical connection between pipe joint are more easily facilitated.

Embodiments using a central retrieval/electrical conduit cable can use a single combination drilling/casing string of pipe that may be rotated in either direction (bi-rotational). Such combination drill pipe/casing have properties and design characteristics that allow a reversible connection to a bottom hole assembly (BHA) and drilling device to allow the BHA to be repaired, replaced or modified without removing any of the single combination drilling/casing pipe system.

The embodiments of this invention increase the efficiency or the drilling of wells, particularly oil and gas wells, and decrease their cost by using a single of combination drill/casing pipe system designed to provide all the functions necessary to drill, protect and prepare a well for its intended purpose and in the use of dual drilling motors.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic view, not to scale, of the components of an embodiment of the invention.

FIG. 2A is a plan elevation side view of and embodiment of the invention showing a pipe connection for composite pipe with electrical connections and snap ring.

FIG. 2B is a plan elevation top view of and embodiment of the invention showing a pipe connection for composite pipe with electrical connections and snap ring.

FIG. 3 is a plan elevation side view of and embodiment of the invention showing a pipe connection for composite pipe with electrical connections and flexible wedge connections.

FIG. 4A is a plan elevation side view of and embodiment of the invention showing command, control, data transmission and electrical power connections in a wireline retrievable cable.

FIG. 4B is a plan elevation top view of and embodiment of the invention showing command, control, data transmission and electrical power connections in a wireline retrievable cable.

FIG. 5 is a plan elevation side view of and embodiment of the invention showing a top side pipe connection for composite pipe with electrical connections and snap ring.

All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific implementations (embodiments) which may be practiced. These implementations are described in sufficient detail to enable those skilled in the art to practice the implementations, and it is to be understood that other implementations may be utilized. Further, logical, mechanical, and other changes may be made without departing from the scope of the implementations. The following detailed description is, therefore, not to be taken in a limiting sense.

In conventional drilling operations drilling mud is customarily used, and it has been convenient to use mud motors. While electric drill motors have many advantages, they have seen limited use because of the complexity of getting sufficient electric power to them. The present system solves that difficulty by use of a retrieval cable/electrical conduit string or power cable disposed in the walls or attached to the walls of the wellbore casing. The system will operate as in proven down hole drilling, under reaming, logging and steerable assembly that is bi-rotational, powered by a proven down hole electric motor and optionally a combination of an electric and mud motors. The electric down hole motors make hole better due to their ability to regulate speed and torque but have not been successful because of electrical connection problems of the conductor cable sections. The electrical drilling motor is powered through the continuous insulated cable that is may also be used to run in and withdraw the drilling assembly. Changing the direction of rotation of the electric drilling motor is simply a change of polarity.

Thus, the present invention comprises methods and apparatus for utilizing a downhole electric motor or motors for drilling in a well casing with retrieval/electrical conduit cable capable of reliability supplying sufficient electric power to drive the electric motor(s) and other components. The cable may be a retrieval cable with electrical conduits included or the electrical conduit may be disposed in or attached to the casing. It is an important aspect of the invention that joints of the casing pile joint be substantially permanent connected and connected in a way that they cannot rotate relative to each other. In some embodiments, the casing may be a combination drill pipe/casing in which the combination drill/casing pipes is rotated to rotate the drill bits, preferable in combination with downhole drive motors. This system uses a single combination drilling/casing string of pipe that is reversibly connected to the drill bit component of a BHA that may be rotated in either direction (bi-rotational) and having properties and design characteristics that allow a connected bottom hole assembly and drilling device to be repaired, replaced or modified without removing any of the single combination drilling/casing pipe system. This system works best with a central retrieval cable having electrical conduits therein sufficient to drive the electric motors enclosed.

The invention consists of two sets of embodiments;

1) systems that utilized electric drilling motor or motors configured for bi-directional drilling; and 2) systems for connecting a combination drilling/casing pipe string to allow drilling and casing with a single pipe array in combination with electric driven drilling motor(s). The effective use of electric drill motor is enabled by means to ensure adequate continuous electric power by providing either electrical lines attached to the drill string by a suitable cable system suspended in the casing. Composite polymer drilling/casing pipe is preferred for attaching electrical connections as the wiring can be incorporated in the wrapping during manufacture and electrical connection between pipe joints are more easily facilitated. For both sets of embodiments, pipe joints in a pipe string will be joined in substantiality permanent connection to enable them to be rotated in either a clockwise or counterclockwise direction. The joined combination pipe joint is designed to withstand the operational forces of tension, compression, torsion, bursting, collapse and flexing that can be required or encountered in its operation, to protect the drilled hole and to provide circuits for command, control, data transmission and electrical power to the down hole devices contained in the wire line retrievable BHA.

For one subset of embodiments, a surface operated insulated cable is designed to provide means to retrieve the drill motor(s) and/or BHA, provide circuits for control command, data transmission and electric power to the downhole devices included in the BHA. The lower end of the combination pipe contains a seating device to receive and accommodate a bi-rotational bottom hole assembly (BHA) that can be operated by a down hole bi-rotational hydraulic mud motor, by a downhole bi-rotational electric motor or by any combination of any of the above power sources, consisting primarily of a bi-rotational drilling device and bi-rotational under reaming device and other ancillary devices as desired. This BHA may also include a locating device), steering device, logging device, subs and other attendant devices all of which are lowered into the receiving and seating device contained at the lower end of the combination pipe, by a surface operated cable. In order to renew, repair or modify any part of the aforementioned drilling assembly the BHA can be unlocked from the combination pipe seating device and removed by a surface operated retrieval cable. The need to remove and reinstall pipe to renew, repair or modify any part of the BHA is eliminated. When the desired depth to cement the pipe is reached the BHA is unlocked (electrically operated latch connecting the cable and top of BHA and/or motor) and removed by its surface operated cable and cement is circulated into to the annular space between the wall of the drilled hole and the outside diameter of the combination pipe. Subsequently another string of smaller diameter combination pipe, containing another bottom hole seating device to receive another desired BHA is lowered into the already cased hole and a new smaller hole is continued to be drilled to next desired depth and then that smaller string of combination pipe is then cemented into place. This process continues to the total desired depth and the final string of combination is cemented in place.

Referring to the drawing, FIG. 1 is a schematic of the components of an embodiment of the invention. It is representative and not to scale. In the figure, 104 is the casing pipe, 110 is the insulated cable that is used to suspend the BHA, 102, and to pull the electric motor and/or the BHA out of the hole. Thus, the drill pipe is not removed as in customary drilling with rotating drill pipe but once inserted in place remains in place. The item 105 is the electric drill motor and 114 is a second motor, preferable a mud motor—these two motors may comprise the dual motor system and are capable of rotation in either direction, clockwise and counterclockwise. In this embodiment the casing pipe is connected to the BHA by a locking pin 108 and supported with a spacer 107. Mud 136 passed down through annular space in the component 112 which is an electrically operated connector to connect the BHA and/or motor to the retrieval cable and thus connects the cable to the top 106 of the BHA and on to the drill bit 130. Connector 112 also has means to connect the electrical conduit in the cable or the cable disposed in or on a casing pipe string. The drill bit has cutting teeth in opposite directions to allow drilling in either direction—clockwise or counterclockwise. Item 120 represents measuring and logging systems and items 122/123, 126/127 and 117/118 are a stabilizer and 124 and are a rotary steering system for slant drilling. An expandable reamer 116 is activated on demand to enlarge the diameter of the hole to allow casing to be advanced.

The retrieval cable will consist of one or more electrical lines (410 in FIG. 4), lines for control of the motors, valves, latches and the like and lines for transmittal of logging and other collected data. FIG. 4 is drawing of a commercial cable useful for the motor/BHA retrieval embodiment the invention. The cable 406 and 408 is attached to head 404 and attachment cage 403. Strands of electrical cable 410 encased in sheathing 409 are disposed inside the center of the cable bundle. Item 402 is the cable head wireline. The cable will be coiled a on a mandrel at the surface. It is preferred that the cable be made into discrete sections, as for example of about 5000 feet in length. This allows the cable to be transported as needed and reduces the weight that would be needed to be transported if the cable was one continuous string. The sections can easily be connected using efficient and reliable mechanical and electrical connectors. It is preferred that the section be of different sizes with the smallest diameter (and therefore lower weight) as the first section and subsequent section being of larger diameter. The principle weight that the retrieval string needs to lift is the weight of the BHA and of the cable itself. By sectioning the heavier and stronger section at the top of the string will bear the greatest weight and the smaller lower section will reduce the overall weight of the string but be sufficient strength to carry the load without the weight of the entire cable.

The representation of components in FIG. 1 is applicable to embodiments in which electrical power is supplied by central cable that is used to retrieve and return the motor and/or BHA out of the hole as each join to casing is added and embodiments where power lines are encased in or attached the casing pipe and electrical connection completed as each pipe joint is added. The wireline cable retrieval embodiments require more labor and handling but is a robust and rugged system that ensures good electrical connection. The embodiments that provide electrical connection in or attached to the pipe string are possible because of the advance in technology and polymer pipe science and provide considerable efficiencies and not having to connect and disconnect pipe.

Cast composite polymer pipe is best suited for the second set of embodiments but metal pipe can also be used with attached electrical conduit lines. A very suitable composite polymer pipe is available from Advanced Composite Products & Technology, Inc. Such pipe consists of materials made of carbon fiber and epoxy resin. The mechanical properties are comparable to steel at less than half the weight. Composite polymer pipe is discussed in an article by Gary L. Covatch and James Heard, Composite Drill Pipe Perfect Fit for Short-Radius Drilling in American Oil & Gas Reporter Article. Use of these advanced tubulars are disclosed in U.S. Pat. Nos. 8,123,888 and 7,604,949 and other issued patents. The disclosures of these two patents are incorporated herein by reference.

The problem with the use of electrical conduits attached to or inserted into polymer pipe has been the in making secure and permanent electrical connections between pipe joints. The present invention presents solutions to that difficulty of connecting and disconnecting pipe. Polymer composite drill and casing tubulars with electrical wiring woven into the fiber wound walls. See, for example, www.ogj.com/articles/print/volume-97/issue-43/in-this-issue/drilling/composite-drill-pipe-research-planned.html—“The US Department of Energy selected Advanced Composite Products & Technology Inc. (ACPT), Huntington Beach, Calif., to head a team to develop a “smart drilling system. “The 5.5-in. drill pipe would be made from a carbon fiber-epoxy resin similar to the material used in golf-club shafts. High-speed data communications capabilities would be woven into the composite material to transmit drilling information.” Such tubulars (pipe) are ideal for embodiments of this invention.

FIGS. 2A and 2B represent one embodiment of a suitable connection means, 200, for polymer composite casing pipe that not only connect the pipe joint together but also allows permanent secure electrical connections. The electrical conduits provide electrical power and logging and control cables to be connected from topside equipment and the BHA components. A male joint of polymer pipe 201 is fitted into a female section of pipe 216. Electric and logging and control cables, 320 and 316 are encased in the walls of the pipe joints. Each joint of pipe will have a male section on one end and female section on the other end. As the casing string is made up the male section of a top joint is fitted into a female lower section of joint. The female section has side walls 202. Lock pin 206 holds the joints together and O rings 204 and 208 seal the connection. The lower end of the male section has a slot 214 into which fits a plug 212 on the top side of the female section joint so that when joined an electrical connection is completed between the electrical line 320 and 316. A guide slot 218 in FIG. 2B facilitates aligning the connections. An O ring 210 seals the electrical connection. Pipe joints with this configuration may also be joined by a suitable fast drying adhesive such as epoxy adhesive. The adhesive may be sprayed or otherwise applied on the male and/or female section of the joints or may be placed in the female section in an encasement that will be broken, and the adhesive released, when the pipe joints are pushed together.

FIG. 3 illustrates another method of composite pipe/electrical connection, 300. The male section of an upper pipe, 312 has a tapered end with compressible fingers, 305, with a shoulder that fits into the upper female section of a lower pipe 303 and 304. The electrical conduit line, 302, connection is made at 310 in the same way as the connection in the embodiment of FIGS. 2A and 2B. When the male and female sections are pressed together the walls of the section 303 slightly expand to allow the tapered compressible fingers of the male section to be inserted. When seated the shoulder of the tapered section engages a shoulder of the female section to fixedly join the sections together and O ring 306 seals the pipe joints. An O ring 311 seals the electrical connection.

FIG. 5 is an embodiment of a surface fitting to attach to the pipe joints to maintain electrical connection when adding pipe joint to the casing string. An upper pipe 501 has a female bottom section 502 that fits into which a male upper section, 506, of the next lower pipe joint 512 fits and secured by a pin 504 (that can be released to disconnect the pipe joints. Electrical connection between the pipe joint is made by connection of 509 into 505. O rings 507 seal the electrical joints and 518 is the snap ring release pin.

Method of Drilling with the Above Described Systems

In the operation of embodiments with a central retrieval cable, the BHA and electric motor are connected with joint connections as described above at the surface of the well with the retrieval disposed in the joint. The drill bit is rotated with the motor(s) and. Combination drill/casing pipe to a depth a of at least the length of the joint. An under reamer is engaged to expand the diameter of the hole and the motor and/or BHA pulled to the surface and inserted into the next joint of pipe. The motor and/or BHA is lowered into the hole and drilling continues. When the joint depth is obtained the hole is enlarged and the motor and/or BHA is pulled and another joint attached. This procedure continues until the desired depth is reached. Electrical connection is made with each joint of pipe attached. In embodiment with electrical conduit in the pipe walls the same procedure is used and the electrical connections made as described in respect FIGS. 2A, 2B and 3. As each joint is attached the BHA and motor are connected to the cable and electrical supply and released as appropriate. If the combination drill pipe casing is used, the BHA is electrically latched to the wall of the lower joint.

The bi-rotational ability of this system allows the well to be drilled in a clockwise direction the motor or pipe rotation reverses and the well drilled in the opposite direction. This reduces wear and tear on the drill bits and helps overcome and cause for the drill bit sticking. By drilling in both directions, the need to remove the BHA and drill bits for repair and replacement is greatly reduced and

It will be readily apparent to those skilled in the art that many variations of the invention may be employed without deviating from the scope of the claims. Many configurations of the invention within the scope of the claims, but not illustrated in the drawings, will be readily apparent to those skilled in the art having the benefit of this disclosure. 

1. A system for drilling a well comprising: a) a well casing consisting of pipe joints connected together in a way to allow rotation of the joints in clockwise or counterclockwise direction; b) a bottom hole assembly disposed in the connected pipe joints having a drill bit that is effective for rotation in a clockwise or counterclockwise direction; c) an electric motor or motors of sufficient power to drive the drill bit and which can be operated to rotate the drill bit in a clockwise or counterclockwise direction; and d) means for supplying sufficient electric power to the electric motor or motors to drive the drill bit.
 2. The system of claim 1 wherein the system is suspended from a cable having electrical conduits releasably connecting the electric motor and components of the bottom hole assembly.
 3. The system of claim 2 wherein the cable is constructed of discrete lengths of different diameters, the smallest diameter cable being the cable nearest the bottom hole assembly.
 4. The system of claim 1 wherein the means for supplying electric power is electrical conduits disposed in or attached to the pipe joint with means to electrically connect the conduits electrically at each joint connection.
 5. The system of claim 4 wherein the pipe joints are composite polymer pipe.
 6. The system of claim 1 comprising a mud motor in addition to the electric motor or motors.
 7. The system of claim 1 wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and in which the bottom end is tapered with a shoulder on the taper configured to fit into the top end of second pipe joint having a top end and bottom end that has a side walls describing an annular space to receive the taper bottom end of the first joint and which has a shoulder configured to mate with the shoulder of the first joint when the first and second pipe joints are pressed together.
 8. The system of claim 1 wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and a second pipe joint having a top end and bottom end that has a side walls describing an annular space with an inside wall to receive the bottom end of the first joint and which has a retractable lock pin in an inside wall of the annular space of the second pipe that is configured to engage an opening in a wall of the first joint.
 9. The system of claim 1 wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and a second pipe joint having a top end and bottom end that has a side walls describing an annular space with an inside wall to receive the bottom end of the first joint and which a fast-drying adhesive is placed between the annular space of the second pipe and the bottom end of the first pipe.
 10. The system of claim 7 comprising means to connect an electrical conduit in the first pipe joint to an electrical conduit in the second pipe joint to make a secure electrical connection.
 11. The system of claim 8 comprising means to connect an electrical conduit in the first pipe joint to an electrical conduit in the second pipe joint to make a secure electrical connection.
 12. The system of claim 1 wherein the connected pipe joints are connected to the bottom hole assembly and configured in a manner to allow rotation of the connected pipe joint to rotate the drill bit disposed in the bottom hole assembly.
 13. A method of drilling wells comprising: 1) providing a) a well casing consisting of pipe joints connected together in a way to allow rotation of the joints in clockwise or counterclockwise direction; b) a bottom hole assembly disposed in the connected pipe joints having a drill bit and retractable under reamer that is effective for rotation in a clockwise or counterclockwise direction; c) an electric motor or motors of sufficient power to drive the drill bit and retractable under reamer and which can be operated to rotate the drill bit in a clockwise or counterclockwise direction; and d) means for supplying sufficient electric power to the electric motor or motors to drive the drill bit and retractable under reamer; 2) providing electric power to the electric motor to rotate the drill bit and retractable under reamer in a clockwise direction; 3) periodically changing direction of rotation of the motor to rotate the drill bit in a counterclockwise direction.
 14. The method of claim 13 wherein: the bottom hole system is suspended from a cable having electrical conduits releasably connecting the electric motor and components of the bottom hole assembly and wherein the cable is constructed of discrete lengths of different diameters, the smallest diameter cable being the cable nearest the bottom hole assembly or wherein the means for supplying electric power is electrical conduits disposed in or attached to the pipe joint with means to electrically connect the conduits electrically at each joint connection.
 15. The method of claim 13 wherein the pipe joints are composite polymer pipe.
 16. The method of claim 13 comprising a mud motor in addition to the electric motor or motors.
 17. The method of claim 13 wherein the connected pipe joints are connected to the bottom hole assembly and configured in a manner to allow rotation of the connected pipe joint to rotate the drill bit and retractable under reamer disposed in the bottom hole assembly and the bottom hole assembly is reversibility attached to the drill pipe and the drill rotated in a clockwise or counterclockwise direction
 18. The method of claim 17 wherein the drill bit and retractable under reamer is rotated by an electric motor, a mud motor and rotation of the connected pipe joints. 